1. Field Of The Invention
The present invention relates to magnetic tape recorders. More specifically, the present invention is directed to a playback circuit for magnetic tape recordings.
2. Description Of The Prior Art
When data is recorded on a magnetic tape and subsequently reproduced at a preselected tape speed, the amplitude vs. frequency function at the output of the reproduce apparatus is a non-linear characteristic. The characteristic is primarily the result of the read head frequency response and is unique to each tape speed. The prior art solution to this problem which requires linearization of the read head output signal for most applications, including the density digital recording, was to use a separate set of equalization networks for each tape speed. These networks are switched in when a tape speed was selected to a multiple tape speed recorder to provide equalization at that tape speed. Because of the complexity and cost of these traditional equalizer networks, it was common practice to provide only a limited number of tape speed choices usually limited to discrete binary speed steps. Accordingly, it would be desirable to provide a speed orineted equalizer amplifier which provides equalization at the traditional binary speed steps but also at arbitrarily variable size speed steps in between each of the conventional binary speeds of the tape.